In a digestive system surgical operation, it is common to anastomose (to join by anastomosis) a duct or tube buried inside a parenchymal organ such as liver or pancreas with a hollow organ such as a digestive tract.
FIGS. 16A and 16B schematically show a conventional method for anastomosing a thin-diameter duct of a parenchymal organ to a digestive tract. As shown in FIGS. 16A and 16B, buried inside a pancreas P is a dead-end pancreatic duct D having an aperture formed on the cut end of the pancreas P. In order to communicate the pancreatic duct D with digestive tract K, this anastomosis operation begins by forming a small incision on the digestive tract K at a position aligned with the pancreatic duct D. Subsequently, a curved needle having a suture is vertically penetrated from its cut end into the pancreas P where the needle travels along its arc into the pancreatic duct D. The curved needle then passes through the duct D to penetrate from the small incision into the lumen of the digestive tract K. And then, the needle passes through the wall of the digestive tract K at the position opposing to the cut end of the pancreas P and travels through the tissue of pancreas P to reach duct D again. By repeating this procedure several times, the pancreas P is sutured to the side wall of the digestive tract K in the manner that the duct D can communicate with the lumen of the digestive tract through the small incision.
Such a thin diameter duct of a parenchymal organ makes anastomosis of the duct and another organ difficult. Using a magnifying glass or operating microscope does not overcome this difficulty because it is cumbersome to ensure a sufficient operating field around a thin-diameter duct, in particular when it is buried in a parenchymal organ. For a conventional anastomosis operation, a curved needle (which is, for example, 0.1 mm in diameter and 13 mm in length and ½ circle) connected to a suture is generally used. In a conventional anastomosis operation, a surgeon grips such a curved needle by use of a needle-carrier and drives the needle along its arc to place the connected suture at a desired position. However, it requires not only considerable surgical skill but also substantial time to precisely drive the needle without unduly invading a thin-diameter duct and surrounding parenchymal organ.
Japanese Patent Publication Number H04-263846 discloses one type of a conventional anastomosis auxiliary tool. The disclosed tool is directed to a surgical suture guide that can be used by surgeons without requiring advanced training. The tool comprises a hard metal portion having a slit for guiding a needle. The hard metal portion is inserted from an external urethral meatus into a urinary duct to facilitate an anastomosis operation for urethral alveolares. Thus, the disclosed tool can be used for anastomosing a tube only when the tube is exposed from surrounding tissues. While this type of anastomosis auxiliary tool can be used for anastomosing a movable urethral tube by inserting the tool in a retrograde fashion from a thick-diameter external urethral meatus to a position where the urethral tube is connected to another tissue, it would be difficult to arrange the disclosed tool into a dead-end thin-diameter duct of a parenchymal organ which has lower mobility.
Thus, the conventional anastomosis auxiliary tool cannot be applied to procedures for anastomosing a dead-end thin-diameter duct of a parenchymal organ with a hollow organ such as a digestive duct. Particularly, it is difficult to ensure that a suture is arranged at a desired position for anastomosis in a thin-diameter duct. Accordingly, there is a need to provide a surgical tool to assist a surgeon in effectively anastomosing such a dead end duct without unduly invading a surrounding tissue of a parenchymal organ.